Tunable bandpass filter

Abstract

This tunable bandpass filter is provided with: a conductive member having a plurality of resonance rods protruding so as to be aligned in a single plane; a dielectric plate disposed parallel to the single plane; a drive part which is attached to the dielectric plate and drives the dielectric plate in directions parallel and perpendicular to the single plane; and a waveguide containing at least the resonance rods and the dielectric plate.

The invention claimed is: 
     
       1. A tunable bandpass filter comprising:
 a conductive member including a plurality of resonance rods protruding in such a way as to be aligned in a single plane; 
 a dielectric plate disposed parallel to the single plane; 
 a driving unit, attached to the dielectric plate, for driving the dielectric plate in directions parallel and perpendicular to the single plane; and 
 a waveguide containing at least the resonance rods and the dielectric plate. 
 
     
     
       2. The tunable bandpass filter according to  claim 1 , wherein the conductive member is a metallic plate and wherein a surface of the conductive member is disposed parallel to the principal surface of the dielectric plate. 
     
     
       3. The tunable bandpass filter according to  claim 1 , wherein the waveguide is divided into two portions across the conductive member. 
     
     
       4. The tunable bandpass filter according to  claim 1 , wherein the conductive member is integral with the waveguide. 
     
     
       5. The tunable bandpass filter according to  claim 1 , wherein the dielectric plate consists of alumina. 
     
     
       6. The tunable bandpass filter according to  claim 1 , wherein a coupling plate is disposed between the adjacent resonance rods. 
     
     
       7. The tunable bandpass filter according to  claim 1 , wherein the driving unit includes a support member attached to the dielectric plate. 
     
     
       8. A tunable bandpass filter comprising:
 a conductive member; 
 a resonance rod protruding from one surface of the conductive member; 
 a dielectric plate disposed parallel to the one surface; 
 a driving unit for driving the dielectric plate in directions parallel and perpendicular to the one surface; and 
 a waveguide containing at least the resonance rod and the dielectric plate.